Episode 34 "Homeward Bound"

Mainframe - z/OSMF Software Management UUID

• What it is: ability to programmatically retrieve a unique value (UUID) which can then be used to find out installation information about the active z/OS system. This function is optional.


• Requires: z/OS 3.1, an SMP/E CSI specific to that software instance, and an installed usermod which is provided by z/OSMF Software Management.


• How it works: once the UUID has been encoded into your z/OS system's LPALIB data set, you can use a REST API to retrieve the UUID. Then, this allows you to use the UUID to run many other REST APIs to look at the installed software with assurance that you are looking at the actively running system software instance. You must ensure that for each new software instance, you install a new UUID. The UUID is also available from the D IPLINFO command.

Performance - Logical Processor Home Addresses

• This is the LPAR's preferred physical location for a specific logical process to be dispatched. Drawer, DCM, chip, core. Degrees of meaning for Verical High, Medium, Low, and Dedicated.


• z16 support is in the SMF 70-1 records, OA62064 . Better than SMF 99-14 in some ways.


• Useful for an analysis of effect of PR/SM weights and HiperDispatch, verify location of ICF and IFL LPARs.


• Logical processor is not always dispatched to its home address. VH and Dedicated will always dispatch to the home processor. Location of memory is not included, although SMF 113 gives hints.


• Might need SMF 99-14 in addition, as it has affinity nodes, which 70-1 doesn't.


• All in all, a very useful advancement in the instrumentation.

Topics - Useful Tips for Debugging a DFSORT E15 Exit

• Martin explores his experiences with DFSORT E15 and offers advice.


• DFSORT E15 is great at flattening records and enhancing filtering. You might find yourself needing to maintain this exit, which others have written.


• Some useful advice is: let the exits do the I/O for you, do a COPY first, stop after one record at first, write diagnostic data into output records, forcing an abend can help, code a SYSUDUMP DD, maintain a DFSORT symbols convention, GETMAIN your working storage, and you can write to the spool.

On the blog

• Marna's blog


• Martin's blogs

So It Goes